https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58605
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=e4379a931d140a71b36eaecceace319837fda321 commit r10-5914-ge4379a931d140a71b36eaecceace319837fda321 Author: Jonathan Wakely <jwak...@redhat.com> Date: Sat Jan 11 00:11:54 2020 +0000 libstdc++: Value-initialize std::atomic for C++20 (P0883R2) This implements the new requirements for C++20 that std::atomic should initialize the atomic variable in its default constructor. This patch does not add the deprecated attribute to atomic_init, but that should be done at some point as it's deprecated in C++20. The paper also deprecates the ATOMIC_FLAG_INIT macro, although we can't apply the deprecated attribute to a macro. PR libstdc++/58605 * include/bits/atomic_base.h (__cpp_lib_atomic_value_initialization): Define. (__atomic_flag_base, __atomic_base, __atomic_base<_PTp*>) (__atomic_float): Add default member initializer for C++20. * include/std/atomic (atomic): Likewise. (atomic::atomic()): Remove noexcept-specifier on default constructor. * include/std/version (__cpp_lib_atomic_value_initialization): Define. * testsuite/29_atomics/atomic/cons/assign_neg.cc: Adjust dg-error line number. * testsuite/29_atomics/atomic/cons/copy_neg.cc: Likewise. * testsuite/29_atomics/atomic/cons/value_init.cc: New test. * testsuite/29_atomics/atomic_flag/cons/value_init.cc: New test. * testsuite/29_atomics/atomic_flag/requirements/trivial.cc: Adjust expected result for is_trivially_default_constructible. * testsuite/29_atomics/atomic_float/requirements.cc: Likewise. * testsuite/29_atomics/atomic_float/value_init.cc: New test. * testsuite/29_atomics/atomic_integral/cons/assign_neg.cc: Likewise. * testsuite/29_atomics/atomic_integral/cons/copy_neg.cc: Likewise. * testsuite/29_atomics/atomic_integral/cons/value_init.cc * testsuite/29_atomics/atomic_integral/requirements/trivial.cc: Adjust expected results for is_trivially_default_constructible. * testsuite/util/testsuite_common_types.h (has_trivial_dtor): Add new test generator.
